<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <ul id="ul">
        <!-- 
        <li>html</li>
        <li>css</li>
        <li>js</li>
         -->
    </ul>

    <!-- <script>
        let arr =[1,2,30]
        for (let i = 0; i < arr.length; i++) {
            let li = document.createElement('li')
            li.innerHTML = arr[i]            
            document.getElementById('ul').appendChild(li)
        }
    </script> -->
    <script>
        //模板
        let template = `
            <ul>
                <% for(let i=0;i<arr.length;i++){} %>  
                    <li>
                        <%= arr[i] %>
                    </li>
                <% } %>
            </ul>
        `
        function compile(tel) {
            let evalExpr = /<%(.+?)%>/g
            tel = tel.replace(evalExpr, '**')
            return tel
        }

        console.log(compile(template));
    </script>
</body>

</html>